MODELING SUPERCRITICAL-FLUID EXTRACTION PROCESS INVOLVING SOLUTE-SOLID INTERACTION

Extraction or leaching of solute from natural solid material is a mass transfer process involving dissolution or release of solutes from a s olid matrix. Interaction between the solute and solid matrix often inf luences the supercritical fluid extraction process. A model accounting for the solute-solid interaction as well as mass transfer is develope d. The BET equation is used to incorporate the interaction and the sol ubility of solutes into the local equilibrium in the model. Experiment al data for the supercritical extraction of essential oil and cuticula r wax from peppermint leaves are successfully analyzed by the model. T he effects of parameters on the extraction behavior are demonstrated t o illustrate the concept of the model.